1. Technical Field
My invention relates to apparatus designed to provide family pets such as cats, dogs, and ferrets with simple and independent yet controlled access to the family home.
2. Background Art
Owners of pet animals have long experimented with various designs of pet entrances to allow their pets independent egress and ingress to the family household. The prior art in the field reflects this experimentation as well as several limitations in the results.
Pet entrances are normally attached at ground level to either an exterior door or wall of the pet owner's home and are designed to be normally closed when not being utilized by the animal. To maintain the normally-closed position, a variety of mechanisms, including springs, elastic doors, and magnetic catches have been used. Although the pet entrance is analogous to the exterior door used by humans for passage into and out of the house, all such pet entrances described in the prior art lack an essential element needed to complete the analogy: a simple means of excluding strangers. The addition of a lock and key to a household's exterior door restricts passage to members of the household and to those authorized by said members. In contrast, the pet entrances described in the prior art normally present any curious animal with easy access to the household interior, provided only that the curious animal is sufficiently small. The sole prior attempt known to the inventor to address this problem utilizes a magnetically-actuated pet door in combination with a magnet-collar to be worn by the pet, as taught by Beckett et al. in "Magnetically Actuated Cat Door", U.S. Pat. No. 4,022,263. Although a partial solution to the stray animal problem, the device of Beckett et al. is a relatively complicated arrangement and is also subject to failure as the result of the pet losing its magnet. In contrast, the present invention utilizes the simplest of designs and depends for the functioning of its lock and key feature upon the pet animal remembering what it has been helped to learn. It is seen that such a simple means of eliminating the stray animal drawback to pet doors constitutes a useful invention and a significant improvement over the prior art. Attention is called to U.S. Pat. Nos. 229,502, 2,758,646, 3,184,803, 3,690,299, 4,022,263, 4,359,198, 4,399,771.